Salvage crews completed setting the wreck of the Costa Concordia upright early Tuesday after a 19-hour-long operation off the Italian island of Giglio, where the huge cruise liner capsized 20 months ago.

Perhaps the most complex and expensive maritime salvage operation ever attempted saw the 114,500-ton ship pulled upright by a series of huge jacks and cables and set on artificial platforms drilled into the rocky sea bed.

The operation was completed at around 4 a.m. local time (10 p.m ET) without any significant problems.

"The ship has been settled onto its platforms," Franco Gabrielli, the head of Italy's Civil Protection Authority, told reporters and a group of cheering residents who waited up into the early hours of the morning to hear the news. "We have accomplished an important step toward removing the ship from the island."

After a salvage operation estimated to have cost more than 600 million euros ($800 million), the hulk will remain in place for months more while it is stabilized and refloated before being towed away to be broken up for scrap.

The so-called parbuckling operation, in which the ship was painstakingly rotated upright, took longer than the 10-12 hours initially estimated, but engineers said the project had gone exceptionally smoothly.

"The rotation happened the way we thought it would happen and the way we hoped it would happen," said Franco Porcellacchia, leader of Costa Cruise's technical team, according to Reuters. "It was a perfect operation, I would say."

Engineers were successful on Monday in shifting the hull of the Costa Concordia ocean liner from the Italian reef where it has lain stricken since January 2012, according to reports. But progress was far slower than anticipated.

Engineers applied some 6,000 tons of force using a system of pulleys and counterweights, Sergio Girotto, a project manager for contractors Micoperi, told The Associated Press. And at around midday local time underwater cameras recorded water swirling around where the metal hull rested on the seabed.

Girotto said the cameras did not, however, reveal any sign of the two people who were not recovered among the 32 killed in the initial incident.

Officials stressed that no appreciable pollution has spewed out of the vessel, where vast stocks of food and drink have sat untouched for almost two years.